Furnace



I. RISDON.

FURNACE:

APPLICATION FILED MAR. 31, 1917.

Patented Sept. 2, 1919.

2 SHEETSSHEET I.

1%Yaa A TTORN E Y I BY W H H D i H H H kn) III, IMZIT H M H w h H H m H H H H H H H H H H H l. RlSDON.

FURNACE.

APPLICATION FILED MAR.3I,19H.

Patented Sept. 2, 1919.

2 SHEETSSHEET 2.

ans Bianc IN VEN TOR IVAN nrsnon, or SEATTLE, wasnrne'ron.

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Specification of Letters Patent.

Application filed March 31, 1917. Serial No. 158,969.

struction of apparatus of this character to render the same more economical 1n the consumption of fuel,with a uniform fire at the different speeds at which the stoking and feeding appliances are actuated.

The invention consists in the novel construction, adaptation and combination of -parts, as will be hereinafter described and claimed.

In the accompanying drawings, Figure 1 is a longitudinal vertical section through a boiler furnace and apparatus embodying my invention which is applied thereto. Fig. 2 is a horizontal section of Fig. 1. Fig. 3 is a transverse sectional view through 3-3 of Fig. 2 and illustrating parts which are not shown in the referred to view. Fig. 4 is a transverse sectional view through 4-4 of Fig. 2.

In the drawings, the reference numeral 5 designates the furnace of a boiler 6, said furnace being inclosed by side walls 7, a rear wall 8 and a front wall 9 having the usual or any suitable stoking and ash-pit openings, as at 10 and 11.

In carrying out my invention, I provide within the aforesaid furnace a supplementary furnace comprising a flaring tunnel member 12, grate members 13 and 14 and an apron member 15 arranged substantially as shown in Figs. 1 and 2. I

Opening into the forward end of the tunnel member 12 is a tube 16 having its forward end closed by aplate 17 and, near the latter, communicating with the discharge end of a coal hopper 16 18 represents a conveyer screw operating within the tube 16 and mounted upon a shaft 19 which may be driven at a slow speed by any suitable means, such, for example, as by worm gearing 20 from a shaft 21 which, in turn, 1s driven through the agency of spur gears 22 from the power shaft 23 of a motor 23 This motor may also be utilized to operate, as by means of belt 24 and pulleys 25, a rotary fan or blower 26 for delivering air under. pressure through ipe 27 and also, through a branch pipe 2 1 provided with a regulating valve 27 into the tube 16 between the outlet end of the latter and thedischarge opening of the fuel hopper 16 Sa1d tunnel member is formed with double walls 12 12 to afford an air chamber 28 WhlCh surrounds the inner wall 12 said chamber being connected from in front with the air sup-ply pipe 27 and at the rear is provided with small outlet holes 12 and communicates by openings 29, 29 respect1 vely, with wing passages 30 and 30 provlded at the outer sides of the sloping side walls 13 of the member 13. The openings 29, 29 are proportioned to furnish as near as practicable an equal quantity of air to each of the passages and within the latter are spaced fins 31 depending from the respective side walls 13 to better distribute the air against the latter for cooling the same. The fins also serve as heat-conducting agents to transfer heat derived from the" referred-to walls to the air in the passages. The air thus heated is delivered from near the rear ends of said passages through holes such as 32 into a compartment 32 from whence it escapes through the grate holes to the bed of fuel for combustion purposes.

' The member 13 is flanked by walls 33 of brick or the like to which it may be rigidly secured, as by embedding the flanges 34 in the respective walls. These walls also serve to support pivots 14 and 15 of members 14 and 15 whereby they may be tilted, as by means of links 35, 36 connecting arms 14 and 15 of the respective members with Patented Sept. 2, T919.

shaker levers 35 36 provided in front of the furnace setting.

The grate members 14 and the apron member have desirably plane upper sur-v faces. The grate members 14 are provided with apertures 14 for the passage of air at natural draft to complete the combustion when the fuel is being fed too rapidly to be entirely burned on said combustion member 13.

The upper surfaces of the grate members and the fuel bearing surface within the tunnel 12 are, ormay be, disposed in substan tially a plane which inclines downwardly at a slight angle .from the front to the rear. The apron, however, when in its normal position, as illustrated in Fig. 1, is inclined somewhat more than the others so as to afford an angle at w whereat clinkers or bodies of combustion products will usually break and slide down upon the apron into a conveyer trough 37 extending through a conduit 38 into a tight casing 39 within which -ber 13 over .the members 14 are deposited the ashes received from the apron.

To effect such transfer of the ashes, I provide a chain conveyer 40 passing about live and dead sprocket wheels 41 and 42 carrying flights or blades 43 which serve to drag the ashes into the receiver casing 39' and also in traversing the outer edge 15* of the apron will cooperate therewith to shear off the clinkered mass which may be projected be yond the apron. The shearing effect of the various blades 43 is, moreover, facilitated by inclining them in the direction of travel. The sprocket wheel 41 may be rotated to drive the chain in any convenient or suitable manner. As shown the shaft 41 of said pulley is operatively connected to the screw conveyer shaft by means of a chain 44 passing about sprocket wheels 44 and 19 on the respective shafts.

In operation, the coal supplied through the hopper 16 is delivered by means of the screw 18 through the tube 16 into the tunnel 12 wherein it is kept moderately cool by reason of the air-cooled tunnel wall 12 The coal, while passing through said tunnel, spreads outwardly so that upon reachto such walls, and enables the fuel bed to be propelled freely through the combustion chamber.

The unconsumed fuel, if any, with clink ered ash travels from the combustion memthrough the apertures 14 of which air under natural draft ascends to effect the complete burning of the fuel. The ash or ashes produced in clinker form in being urged from behind are likely to project for a distance over the edge w, Figs. land 2, of the rearmost mem ber until the weight of the unsupported part will cause it to break and fall upon the apron 15. From the latter it slides into the trough to be broken and carried away by the conveyer blades.

The purpose of the branch pipe 27 is to conduit air into the tube 16 to afford pressure suflicient to create an air current in the tube which will prevent the more volatile gaseswhich may be produced in the tunnelfrom escaping'through the hopper.

The above-described apparatus will operate with a clinkering coal, including nearly all of the lignites, so that'the screw can push, as it were, everything ahead to the trou h. The coal will not clinker to any appreciable amount while being pushed through the aircooled. tunnel, but by being of considerable depth will afford enough resistance to cause the clinkering and clinkered material to be shoved thereby.

In practice, the combustible portion of the fuel is usually consumed before it has reached or passed but a short way over the members. 14. The combustion member is at a high temperature, as is likewise the preheated air which is supplied therethrough into the fuel from below.

The ashes are intended to be carried away by the conveyer therefor and the only purpose of making the members 14 and the apron 15 of the rocking-grate type is to enable an attendant to shake them to break up 100 the mass thereabove when it becomes unduly caked. The apron 15 is disposed considerably below the level of the member 13 above which the greater part of the C0111- bustion occurs, and is accordingly not sub- 105 ected to much heat.

-What I claim, is

1. The combination with a furnace having a combustion chamber provided with an opening in its front wall, of a structure comprising a tunnel member provided with hol low walls extending through said opening, and a combustion member located within said combustion chamber, said combustion member comprising an apertured floor, an air compartment therebelow and with hollow wlng elements which extend to a higher elevation than the floor and afi'ording imperforate side walls therefor, means to supply air under pressure throughtsaid tunnel Walls and the wing elements into said compartment, and means to feed fuel through Eaid tunnel and longitudinally over said oor..

2. The combination with a furnace having a combustion chamber provided with an opening in its front wall, of a structure comprising a tunnel member provided with hollow walls extending through said openmg, and a combustion member located withrename a in said combustion chamber, said combuswhich will obviate the adhering thereto of tion member comprising an apertured floor elinkers traveling in the fuel bed over said 10 with hollow Wing elements which extend to floor, and means to effect the feeding of a higher elevation thanthe floor and afford fuel through said tunnel and the subsequent ing imperforate side Walls therefor, means movement of the fuel bed upon the floor. to supply air under pressure through said Signed at Seattle, Washington, this 22nd tunnel Walls and the wing elements to mainday of March, 1917.

tain the Walls of the latter at a temperature IVAN RISDON.- 

